Composition for improving lubrication ability of diesel fuel and its application

Abstract

FIELD: additives for diesel fuels.SUBSTANCE: composition for improving the lubricity of diesel fuel is proposed, comprising: component A: a dicarboxylic acid monoester selected from dicarboxylic acid monoesters represented by the following formula (I-1): in which n is an integer from 2 to 6, R is a C3-20 hydrocarbyl group , and selected from a maleic acid monoester, a fumaric acid monoester, a citraconic acid monoester, a methylfumaric acid monoester, a 2,3-dimethylmaleic acid monoester, a glutaconic acid monoester, or any combination thereof, or dicarboxylic acid monoesters represented by the following formula (I-2): in which p is an integer from 1 to 8, R is a C3-20 hydrocarbyl group , and selected from a malonic acid monoester, a succinic acid monoester, a glutaric acid monoester, an adipic acid monoester, an azelaic acid monoester, a sebacic acid monoester, or any combination thereof, or monoesters of dicarboxylic acids represented by the following formula (I-4): in which R8 is a C2-10 divalent hydrocarbyl group; R9 is a hydrogen atom or a hydrocarbyl group, R10 is a divalent hydrocarbyl group, and the total number of carbon atoms in R9 and R10 is from 15 to 21, and the total number of double bonds between carbon atoms is from 0 to 3; R11 is a hydrogen atom or a C1-10 hydrocarbyl group ; and component B: a long-chain fatty acid C8-24, a corresponding ester of a polyhydric alcohol or a mixture thereof, wherein the total amount of component A and component B is 100 wt.%, the mass ratio of component A and component B is from 9:1 to 1:9; a method for improving the lubricity of diesel fuel using the proposed composition and a diesel fuel composition comprising the proposed composition.EFFECT: production of a composition that, at a reduced dosage, improves the lubricating ability of diesel fuel.18 cl, 7 dwg, 11 tbl, 32 ex

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202110740397.8, entitled "Composition for Improving the Lubricity of Diesel Fuel, Preparation thereof, and Diesel Fuel Composition," filed on June 30, 2021, the contents of which are hereby incorporated by reference in their entirety.

[0003] Field of technology to which the present invention pertains

[0004] The present invention relates to the field of diesel fuel, in particular to a composition for improving the lubricity of diesel fuel and to the use thereof.

[0005] Background Art of the Present Invention

[0006] With growing environmental concerns around the world, the production of high-quality clean energy has become the development direction of the modern petroleum refining industry, and diesel fuel production standards are gradually improving. Clean diesel fuel is characterized by low aromatic hydrocarbon content, high cetane number, lighter fraction, and low sulfur and nitrogen content. Sulfur is the most harmful element contributing to atmospheric pollutants, so the level of sulfur-containing compounds in diesel fuel is strictly controlled. Clean diesel fuel currently produced is mainly produced through a hydrogenation process, which removes sulfur-containing compounds from diesel fuel while simultaneously reducing the nitrogen-containing compounds and oxygen-containing compounds in diesel fuel.It is known that the lubricity of diesel fuel depends primarily on the level of lubricity-improving additives in the fuel. Polycyclic aromatic compounds, oxygen-containing additives, and nitrogen-containing additives are highly effective lubricity-improving substances. Reduced levels of nitrogen and oxygen compounds reduce the lubricity of the diesel fuel itself, leading to wear and failure of the fuel pump.

[0007] Because low-sulfur diesel fuel exhibits poor lubricity, low-sulfur diesel fuel and ultra-low-sulfur diesel fuel are often treated with lubricity-enhancing compounds (also known as lubricity-enhancing additives or antiwear additives) to improve their lubricity. This method has the advantages of low cost, production flexibility, reduced pollution, and other benefits, and is widely used in industry.

[0008] Compositions for improving the lubricity of diesel fuel are in most cases derivatives of fatty acids, esters of fatty acids, amides or salts. Publication EP 773279 discloses esters of carboxylic acids obtained by reacting a dimer acid with an alcoholamine for use in a composition for improving the lubricity of diesel fuel. Publication EP 798364 discloses salts or amides obtained by reacting fatty acids with fatty amines as additives for improving the lubricity of diesel fuel. EP 1209217 describes the reaction products of saturated fatty acids C 6-50and dimer acids with short-chain oil-soluble primary, secondary, and tertiary amines for use in a diesel fuel lubricity-improving composition. Publication WO 9915607 discloses a reaction product of a dicarboxylic fatty acid with an epoxide for use in a diesel fuel lubricity-improving composition. Most of these technologies utilize the reaction of a fatty acid or dimer fatty acid with an amino alcohol, an amine, and an epoxide, with some reaction starting materials being expensive and demonstrating an overall lubricity-improving effect, while increasing the amount of additive added to the diesel fuel.

[0009] Existing industrial compositions for improving the lubricity of low-sulfur diesel fuel fall into two main types: acid-type lubricity improving compositions and ester-type lubricity improving compositions. The main component of the acid-type lubricity improving composition is a long-chain unsaturated fatty acid such as oleic acid, linoleic acid, linolenic acid and the like, and a typical product is purified tall oil fatty acid. The ester-type lubricity improving composition is an esterification reaction product of the aforementioned fatty acid and a polyhydric alcohol. WO 9417160 A1 discloses the use of oleic acid monoglyceride as a composition for improving the lubricity of diesel fuel.

[0010] Although the fatty acid lubricity improving composition used to solve the lubricity problem of diesel fuel is relatively low in cost, excessive acidity of diesel fuel, increased risk of corrosion, and similar problems can be caused by the high amount of the composition used due to the raising of diesel fuel standards and the reduction of its lubricity. Although the lubricity improving composition containing fatty acid esters can be used in small quantities, there are also problems such as high cost and the risk of emulsification and clouding of diesel fuel modified with the lubricity improving composition when mixed with water.

[0011] CN 109576021 A publication discloses a composition for improving the lubricity of low-sulfur diesel fuel and its production, in which an ester of an unsaturated dicarboxylic acid (maleic acid diester) and a polymerization inhibitor are mixed at a temperature of 150 to 180°C, biodiesel fuel containing tung oil is gradually added, the reaction is continued for a certain time at a temperature of 200 to 240°C, and a lubricity-improving product is obtained by distillation under reduced pressure after the reaction.To obtain the product, the raw material required is tung oil-containing biodiesel, which is rare and unstable, the reaction requires high temperature, the production is difficult, and the most important thing is that the lubricity improvement effect is the most general, and more than 600 ppm of lubricity improving substance is required.

[0012] CN Publication 106929112 A discloses a method for improving the lubricity of low-sulfur diesel fuel, in which the lubricity of diesel fuel is improved by using an esterification reaction product of alkenyl succinic anhydride and a monohydric aliphatic alcohol, but the product exhibits high viscosity and produces an overall effect of improving the lubricity of ultra-low-sulfur diesel fuel (such as diesel fuel for vehicles that meets the national Tier VI emission standard).

[0013] In the article “Effect of Acetic Acid Esters and Dicarboxylic Acid Esters on the Lubricity of Dicarboxylic Acid Esters” published by G. Anatopoulos and E. Lois in Tribology International, 2001, 34(11):749-755), it was reported that the lubricity was improved by adding dicarboxylic acid diesters such as dibutyl adipate, dioctyl adipate, diethyl azelainate, dibutyl azelainate, dioctyl azelainate, diethyl sebacate to low sulfur diesel fuel, but the diester compounds produced unsatisfactory lubricity improving effect and required to be added at an amount of 500 ppm or even more than 1000 ppm.

[0014] Brief Disclosure of the Present Invention

[0015] An object of the present invention is to provide a composition for improving the lubricity of diesel fuel and its use, which can overcome the shortcomings of the prior art and provide a satisfactory improvement in lubricity at a reduced dosage.

[0016] In order to solve the above problem, according to an aspect of the present invention, a composition for improving the lubricity of diesel fuel is provided, comprising:

[0017] Component A: a dicarboxylic acid monoester represented by the following formula (I),

[0018]

[0019] where R1 is a divalent hydrocarbyl group C 1-10 ;

[0020] R2 is a hydrocarbyl group C 1-20 or a fragment having the structure -R3-C(=O)-O-R4;

[0021] R3 is a divalent hydrocarbyl group C 8-24 ;

[0022] R4 represents a hydrogen atom or a hydrocarbyl group C 1-10 ; And

[0023] Component B: Long-chain fatty acid C 8-24 , the corresponding ester of a polyhydric alcohol or a mixture thereof,

[0024] wherein the total amount of component A and component B is from 70 to 100% by weight relative to the total weight of the composition; and

[0025] The mass ratio of component A and component B is from 9:1 to 1:9.

[0026] After intensive study and a huge amount of experiments, the present inventors unexpectedly found that when a dicarboxylic acid monoester represented by the formula (I) and a long-chain fatty acid C 8-24or a corresponding polyhydric alcohol ester are introduced into the composition in a certain ratio, the lubricity of low-sulfur diesel fuel can be significantly improved by adding only a small amount of the composition thereto, and that the composition exhibits an unexpected synergistic effect, due to which it is significantly superior to the corresponding industrially used compositions containing fatty acids or fatty acid glycerides for improving lubricity, and as a result, the required amount of the composition for improving lubricity is significantly reduced.

[0027] According to a further aspect of the present invention, a method is provided for improving the lubricity of diesel fuel, comprising adding a composition for improving the lubricity of diesel fuel according to the present invention to a low-sulfur diesel fuel, wherein the composition for improving the lubricity of diesel fuel is preferably added in an amount of 10 to 400 parts per million based on the weight of the low-sulfur diesel fuel.

[0028] According to a further aspect of the present invention, there is provided a diesel fuel composition comprising a low-sulfur diesel fuel and a composition for improving the lubricity of the diesel fuel according to the present invention, wherein the composition for improving the lubricity of the diesel fuel is present in the diesel fuel composition in an amount that is preferably from 10 to 400 parts per million based on the weight of the low-sulfur diesel fuel.

[0029] The composition for improving the lubricity of diesel fuel described in the present invention is simple and convenient to produce from readily obtainable raw materials, and is also unexpectedly superior in its effect to conventional compositions for improving lubricity containing fatty acids or fatty acid esters, and can significantly improve the lubricity of low-sulfur diesel fuel, so that the amount added can be significantly reduced, and the cost of using it can also be significantly reduced.

[0030] In addition, the composition for improving the lubricity of diesel fuel according to the present invention also produces the effect of improving the lubricity of gasoline and jet fuel.

[0031] Other characteristics and advantages of the present invention will be described in detail in the detailed description provided later in this document.

[0032] Brief description of figures

[0033] The figures that form part of the description of the present invention are intended to facilitate the understanding of the present invention and are not to be construed as limiting. The present invention may be construed with reference to the figures in conjunction with the detailed description provided later herein. The figures include:

[0034] Fig. 1 illustrates the infrared spectrum of the product obtained in Preparative Example 1;

[0035] Fig. 2 illustrates a photograph of a wear scar for diesel fuel A used in the examples;

[0036] Fig. 3 illustrates a photograph of a wear scar for diesel fuel A, to which the composition obtained in Example 1 was added in an amount of 100 mg / kg, WS1.4=226 μm (wear scar diameter for a standard water vapor pressure of 1.4 kPa);

[0037] Fig. 4 illustrates a photograph of a wear scar for diesel fuel A, to which the composition obtained in Example 1 was added in an amount of 70 mg / kg, WS1.4=305 μm;

[0038] Fig. 5 illustrates a photograph of a wear scar for diesel fuel B used in the examples;

[0039] Fig. 6 illustrates a photograph of a wear scar for diesel fuel B, to which the composition obtained in Example 1 was added in an amount of 100 mg / kg, WS1.4=256 μm;

[0040] Fig. 7 illustrates a photograph of a wear scar for diesel fuel B, to which the composition obtained in Example 1 was added in an amount of 200 mg / kg, WS1.4=189 μm.

[0041] Detailed Disclosure of the Present Invention

[0042] The present invention will be described in detail below with reference to the figures and the presentation of corresponding specific embodiments. It should be noted that the specific embodiments of the present invention are presented for illustrative purposes only and are not intended to be limiting in any way.

[0043] Any specific numerical values, including the endpoints of numerical ranges, that are described in the context of the present invention are not limited to the corresponding exact values, but they should be construed as covering all values ​​​​near the stated exact values; for example, all values ​​​​within ±5% of the stated exact value. In addition, with respect to any numerical range described herein, arbitrary combinations can be made between the endpoints of the range, between each endpoint and any specific value within the range, or between any two specific values ​​​​within the range to obtain one or more new numerical ranges, wherein one or more of these new numerical ranges should also be considered as specifically described in the present invention.

[0044] Unless otherwise defined, the terms used in this document have the meanings commonly understood by those skilled in the art; and if the terms are defined in this document and their definitions differ from the common understanding in the art, the definitions provided in this document shall prevail.

[0045] According to the present invention, the term "hydrocarbyl group" generally means a variety of groups that are formed by the removal of one hydrogen atom from saturated or unsaturated organic compounds, consisting of carbon atoms and hydrogen atoms, such as a variety of aliphatic, alicyclic and aromatic compounds. Specific exemplary hydrocarbyl groups are, but are not limited to, linear or branched alkyl groups (also referred to as the term "alkyl"), linear or branched alkenyl groups (also referred to as the term "alkenyl"), linear or branched alkynyl groups, cycloalkyl groups, alkylcycloalkyl groups, cycloalkylalkyl groups, alkenylcycloalkyl groups, cycloalkylalkenyl groups, cycloalkenyl groups, alkylcycloalkenyl groups, cycloalkenylalkyl groups, aryl groups, arylalkyl groups, alkylaryl groups and the like groups.

[0046] According to the present invention, the term "divalent hydrocarbyl group" (also referred to as the term "alkylene group") generally means various groups that are formed by removing two hydrogen atoms from saturated or unsaturated organic compounds consisting of carbon atoms and hydrogen atoms, such as various aliphatic, alicyclic and aromatic compounds.Specific exemplary divalent hydrocarbyl groups include, but are not limited to, linear or branched alkylene groups (also referred to as "divalent alkyl"), linear or branched alkenylene groups (also referred to as "divalent alkenyl"), linear or branched alkynylene groups, cycloalkylene groups, -alkyl-cycloalkyl-, -cycloalkyl-alkyl-, -alkenyl-cycloalkyl-, -cycloalkyl-alkenyl-, cycloalkenylene, -alkyl-cycloalkenyl-, -cycloalkenyl-alkyl-, arylene groups (also referred to as "divalent aryl"), -aryl-alkyl-, -alkyl-aryl-, and the like groups.

[0047] According to the present invention, unless otherwise specified, the “hydrocarbyl group” and the “divalent hydrocarbyl group” may be substituted or unsubstituted, preferably unsubstituted.

[0048] According to the present invention, the term "alkenyl" means aliphatic hydrocarbyl groups that contain at least one (for example, from 1 to 5, preferably from 1 to 3) double bond between carbon atoms, which may be in the main chain or in the side chain of the alkenyl group, and do not contain any triple bond between carbon atoms in the carbon chain, such as vinyl, propenyl, allyl and the like groups.

[0049] According to the present invention, the term "alkenylene" means aliphatic hydrocarbylene groups that contain at least one (for example, from 1 to 5, preferably from 1 to 3) double bond between carbon atoms, which may be in the main chain or in the side chain of the alkenyl group, and do not contain any triple bond between carbon atoms in the carbon chain, such as vinylene, -(CH2=)C-CH2-, -(CH3)C=CH-, -(CH3)C=C(CH3)- and the like.

[0050] According to the present invention, the expressions "optionally substituted" and "substituted or unsubstituted" may be used interchangeably to indicate that the group to which such expression refers may be an unsubstituted group or a substituted group containing one or more substituents.

[0051] According to the present invention, unless otherwise specified, the term "substituted" means that the group to which such term refers is substituted and contains one or more, for example, one, two or three groups, which may be selected as linear or branched hydrocarbyl groups C 1-10 , halogen atoms, hydroxyl groups, carboxyl groups, ester groups, ether groups, nitro groups and amino groups, preferably linear or branched hydrocarbyl groups C 1-4, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, vinyl, propenyl and allyl groups and the like.

[0052] In the context of the present invention, in addition to those items specifically indicated, any item or items that are not mentioned should be considered identical to items known in the art, without any modification. Furthermore, any of the embodiments described herein can be arbitrarily combined with one or more embodiments described herein, and the technical solutions or ideas obtained as a result of such a combination should be considered as part of the original disclosure or original description of the present invention, but should not be considered as new items that were not described or suggested herein, unless it is clear to a person skilled in the art that such a combination is obviously unreasonable.

[0053] All patent and non-patent documents cited in this document, including but not limited to textbooks and journal articles, are hereby incorporated by reference in their entirety.

[0054] According to a first aspect of the present invention, there is provided a composition for improving the lubricity of diesel fuel, comprising:

[0055] Component A: a dicarboxylic acid monoester represented by the following formula (I),

[0056]

[0057] where R1 is a divalent hydrocarbyl group C 1-10 ;

[0058] R2 is a hydrocarbyl group C 1-20 or a fragment having the structure -R3-C(=O)-O-R4;

[0059] R3 is a divalent hydrocarbyl group C 8-24 ;

[0060] R4 represents a hydrogen atom or a hydrocarbyl group C 1-10 ; And

[0061] Component B: Long-chain fatty acid C 8-24 , the corresponding ester of a polyhydric alcohol or a mixture thereof,

[0062] wherein the total amount of component A and component B is from 70 to 100% by weight relative to the total weight of the composition; and

[0063] The mass ratio of component A and component B is from 9:1 to 1:9.

[0064] Depending on the circumstances, small amounts of additional components such as diesel fuel, organic solvents, unreacted raw materials (such as alcohols or phenols), reaction by-products (such as diester compounds of dicarboxylic acids) and the like may be present in the diesel fuel lubricity improving composition of the present invention in addition to component A and component B, but the total amount of said additional components is not more than 20 mass%, preferably not more than 10 mass%, and more preferably not more than 5 mass%, for example not more than 1 mass%, relative to the total weight of the diesel fuel lubricity improving composition.

[0065] According to a preferred embodiment, the total amount of component A and component B is 80 to 100 mass%, and more preferably 90 to 100 mass%, including 91 mass%, 92 mass%, 93 mass%, 94 mass%, 95 mass%, 96 mass%, 97 mass%, 98 mass%, 99 mass% or 100 mass%, relative to the total weight of the composition for improving the lubricity of diesel fuel.

[0066] According to some preferred embodiments, in the composition for improving the lubricity of diesel fuel, component B is a long-chain fatty acid C 8-24 , and the weight ratio of component A to component B is from 8:2 to 2:8, preferably from 7:3 to 3:7, and more preferably from 7:3 to 5:5, such as from 7 to 6:4.

[0067] According to some preferred embodiments, in the composition for improving the lubricity of diesel fuel, component B is an ester of a polyhydric alcohol and a long-chain fatty acid C 8-24 , and the weight ratio of component A to component B is from 8:2 to 1:9, preferably from 8:2 to 2:8, and more preferably from 5:5 to 2:8, such as from 4:6 to 3:7.

[0068] According to some particularly preferred embodiments, the composition for improving the lubricity of diesel fuel consists essentially of component A and component B, that is, contains only component A and component B, excluding inevitable impurities (such as unreacted starting materials and reaction by-products), component B is a long-chain fatty acid C 8-24, and the composition contains from 20 to 80 wt. %, preferably from 30 to 70 wt. % and more preferably from 50 to 70 wt. %, including from 60 to 70 wt. % of component A, and from 20 to 80 wt. %, preferably from 30 to 70 wt. % and more preferably from 30 to 50 wt. %, including from 30 to 40 wt. % of component B relative to the weight of the composition.

[0069] According to some particularly preferred embodiments, the composition for improving the lubricity of diesel fuel consists essentially of component A and component B, that is, contains only component A and component B, excluding inevitable impurities (such as unreacted starting materials and reaction by-products), component B is an ester of a polyhydric alcohol and a long-chain fatty acid C 8-24, and the composition contains from 10 to 80 wt. %, preferably from 20 to 80 wt. % and more preferably from 20 to 50 wt. %, including from 30 to 40 wt. % of component A, and from 20 to 90 wt. %, preferably from 20 to 80 wt. % and more preferably from 50 to 80 wt. %, including from 60 to 70 wt. % of component B relative to the weight of the composition.

[0070] The lubricity improving composition according to the present invention can be used in pure form for the purpose of improving the lubricity of a fuel, such as diesel fuel, or it can be used in combination with one or more additional fuel additives, such as phenolic antioxidants, polymeric amine ashless dispersants, flow improvers, cetane improvers, metal deactivators, antistatic agents, corrosion inhibitors, rust inhibitors, demulsifying agents and the like, for the purpose of improving the lubricity and one or more other properties of diesel fuel, as far as is desired.

[0071] Next, component A and component B of the composition according to the present invention will be described in more detail.

[0072] Component A

[0073] According to the present invention, component A is a dicarboxylic acid monoester represented by the following formula (I),

[0074]

[0075] where R1 is a divalent hydrocarbyl group C 1-10 ;

[0076] R2 is a hydrocarbyl group C 1-20 or a fragment having the structure -R3-C(=O)-O-R4;

[0077] R3 is a divalent hydrocarbyl group C 8-24 ;

[0078] R4 represents a hydrogen atom or a hydrocarbyl group C 1-10 .

[0079] According to some preferred embodiments, in the structural formula (I):

[0080] R1 is a divalent alkyl group C 1-10 , divalent alkenyl group C 2-10 or a fragment having the structure - R5-R6-R7, preferably a divalent alkyl group C 1-8 , divalent alkenyl group C2-6 or a fragment having the structure -R5-R6-R7-, and preferably a divalent alkyl group C 1-4 or a divalent alkenyl group C 2-4 ;

[0081] R2 is a hydrocarbyl group C 3-20 , preferably a linear or branched hydrocarbyl group C 3-20 , alicyclic hydrocarbyl group C 4-20 , aryl-substituted hydrocarbyl group C 7-20 or a hydrocarbyl-substituted aryl group C 7-20 and preferably a linear or branched hydrocarbyl group C 3-18 , alicyclic hydrocarbyl group C 4-18 , aryl-substituted hydrocarbyl group C 7-18 or a hydrocarbyl-substituted aryl group C 7-18 ;

[0082] R5 and R7 in each case independently represent a single bond, or a divalent hydrocarbyl group C 1-3 , and preferably each independently represents a single bond or a methylene group;

[0083] R6 is a divalent alicyclic hydrocarbyl group C 3-10 , or a substituted or unsubstituted divalent aryl group C 6-10 , preferably a divalent alicyclic hydrocarbyl group C 4-7 , or a substituted or unsubstituted divalent aryl group C 6-10 , and the total number of carbon atoms in the groups R5, R6 and R7 is 10 or less;

[0084] wherein the said “substitution” means substitution with the introduction of one or more groups, which may be linear or branched hydrocarbyl groups C 1-4 , halogen atoms, hydroxyl group, carboxyl group, ester group, ether group, nitro group, and amino group, preferably linear or branched hydrocarbyl groups C 1-4 .

[0085] According to some preferred embodiments, in the structural formula (I):

[0086] R1 is a divalent hydrocarbyl group C 2-20 and preferably a divalent hydrocarbyl group C 2-8 ;

[0087] R2 is a fragment having the structure -R3-C(=O)-O-R4;

[0088] R3 is a divalent hydrocarbyl group C 8-24 , containing from 0 to 5 double bonds between carbon atoms, preferably a divalent hydrocarbyl group C 16-22 , containing from 0 to 3 double bonds between carbon atoms; and

[0089] R4 represents a hydrogen atom or a hydrocarbyl group C 1-10 , preferably a hydrogen atom or a hydrocarbyl group C 1-4 .

[0090] According to some further preferred embodiments, the dicarboxylic acid monoester of component A is selected from dicarboxylic acid monoesters represented by formula (I-1), (I-2) or (I-3):

[0091]

[0092] where n is an integer from 2 to 6, R is a hydrocarbyl group C 3-20 and preferably a hydrocarbyl group C 4-18 ;

[0093]

[0094] where p is an integer from 1 to 8, R is a hydrocarbyl group C 3-20 and preferably a hydrocarbyl group C 4-18

[0095]

[0096] where m is an integer from 0 to 1, Q is a divalent alicyclic hydrocarbyl group C 3-8 or a substituted or unsubstituted divalent aryl group C 6-10 , and R is a hydrocarbyl group C 3-20 , preferably a hydrocarbyl group C 4-18 .

[0097] According to the present invention, in the structural formula (I-1), (I-2) or (I-3), R may be an aliphatic hydrocarbyl group, an alicyclic hydrocarbyl group or an aryl group. The aliphatic hydrocarbyl group may be linear or branched; it may be a saturated aliphatic hydrocarbyl group or an unsaturated aliphatic hydrocarbyl group; the unsaturated aliphatic hydrocarbyl group may be an aliphatic hydrocarbyl group which may contain at least one double bond between carbon atoms (ethylene bond) or at least one triple bond between carbon atoms (acetylene bond). The alicyclic hydrocarbyl group may be a saturated alicyclic hydrocarbyl group (cycloalkyl group) or an unsaturated aliphatic hydrocarbyl group.An aryl group can be a monocyclic aryl group, or it can be a bicyclic or polycyclic aryl group. Alicyclic and aryl groups can also contain a variety of hydrocarbyl substituents on the carbon ring.

[0098] According to a further preferred embodiment, in the structural formula (I-1), (I-2) and (I-3), linear or branched aliphatic hydrocarbyl groups C can be selected as R 3-20 , alicyclic hydrocarbyl groups C 4-20 , aryl-substituted hydrocarbyl groups C 7-20 or hydrocarbyl-substituted aryl groups C 7-20 and preferably linear or branched alkyl groups C 4-18 .

[0099] According to the present invention, when R is a saturated linear or branched aliphatic hydrocarbyl group, R may be a normal alkyl group or an isomeric alkyl group. When R is an n-alkyl group, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, a mono-n-dodecyl group (lauryl ester group), an n-tetradecyl group, an n-hexadecyl group, an n-octadecyl group or the like may be present, and an n-butyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, an n-decyl group are more preferred.When R is an isomeric alkyl group, isopropyl, isobutyl, sec-butyl, isopentyl, isohexyl, isoheptyl, isooctyl (particularly 2-ethylhexyl), isononyl, isodecyl, isotridecyl, isopentadecyl, isoheptadecyl and the like may be present in this capacity, and sec-butyl, isooctyl (particularly 2-ethylhexyl), isononyl, isodecyl, isoundecyl and isotridecyl may be present in this capacity.

[0100] According to the present invention, when R is an unsaturated linear or branched aliphatic hydrocarbyl group, allyl, 2-butenyl, 3-butenyl, isopentenyl, 3-hexenyl, 2-octenyl, 3-nonenyl, 2-decenyl, 7-dodecenyl, 1,5-hexadienyl, 2,4-nonadienyl, 2,4-decadienyl, 9,11-dodecadienyl, 9-octadecenyl and more preferably 3-hexenyl, 2-octenyl, 3-nonenyl, isopentenyl, 9-octadecenyl may be present as such.

[0101] According to the present invention, when R is an alicyclic hydrocarbyl group, cyclobutyl, cyclopentyl, cyclohexyl, 3-cyclohexenyl, 2-cyclohexenyl or the like may be preferably present, and cyclopentyl, cyclohexyl, 3-cyclohexenyl or 2-cyclohexenyl may be more preferably present.

[0102] According to the present invention, when R is an unsubstituted aryl group, a phenyl group may be preferably present as such; when R is a hydrocarbyl-substituted aryl group, methylphenyl, p-nonylphenyl, p-dodecylphenyl or the like may be preferably present as such; when R is an aryl-substituted hydrocarbyl group, benzyl (phenmethyl), phenethyl, p-dodecylphenyl or the like may be preferably present as such, and benzyl (phenmethyl), p-nonylphenyl, p-dodecylphenyl are more preferably present.

[0103] According to the present invention, the dicarboxylic acid monoester represented by the formula (I-1) is an unsaturated dicarboxylic acid monoester obtained by esterifying one carboxyl group of a linear or branched dicarboxylic acid C 4-8 , containing one unsaturated double bond between carbon atoms.

[0104] Specifically, when n is 2, the dicarboxylic acid monoester represented by the formula (I-1) is maleic acid monoester (i.e., cis-butenedicarboxylic acid monoester), fumaric acid monoester (i.e., trans-butenedicarboxylic acid monoester); when n is 3, the dicarboxylic acid monoester represented by the formula (I-1) is itaconic acid monoester, citraconic acid monoester (i.e., methylmaleic acid monoester), methylfumaric acid monoester (i.e., trans-methylbutenedicarboxylic acid monoester), glutaconic acid monoester or the like; when n is 4, the dicarboxylic acid monoester represented by the formula (I-1) is preferably 2,3-dimethylmaleic acid monoester, ethylmaleic acid monoester, hexenedicarboxylic acid monoester, etc.

[0105] Preferably, as the dicarboxylic acid monoester represented by the formula (I-1), maleic acid monoester, fumaric acid monoester, itaconic acid monoester, citraconic acid monoester, methylfumaric acid monoester, 2,3-dimethylsmaleic acid monoester, glutaconic acid monoester or the like can be selected, and maleic acid monoester and itaconic acid monoester can be selected more preferably.

[0106] More preferably, as the dicarboxylic acid monoester represented by the formula (I-1), maleic acid monoesters represented by the formula (I-1-1) can be selected,

[0107]

[0108] Itaconic acid monoesters represented by the formula (I-1-2),

[0109]

[0110] or itaconic acid monoesters represented by the formula (I-1-3),

[0111]

[0112] where R corresponds to the definition given above.

[0113] Particularly preferably, when R is an n-alkyl group, as the maleic acid monoester of the formula (I-1-1), monomethyl maleate, monoethyl maleate, mono-n-propyl maleate, mono-n-butyl maleate, mono-n-pentyl maleate, mono-n-hexyl maleate, mono-n-heptyl maleate, mono-n-octyl maleate, mono-n-nonyl maleate, mono-n-decyl maleate, mono-n-undecyl maleate, mono-n-dodecyl maleate (lauryl ester), mono-n-tetradecyl maleate, mono-n-hexadecyl maleate, mono-n-octadecyl maleate or the like can be selected, preferably monomethyl maleate, monoethyl maleate, mono-n-propyl maleate, mono-n-butyl maleate, mono-n-octyl maleate, mono-n-nonyl maleate, mono-n-decyl maleate, mono-n-dodecyl maleate or the like, and preferably mono-n-butyl maleate, mono-n-pentyl, mono-n-octyl maleate, mono-n-nonyl maleate, mono-n-decyl maleate or the like;as the itaconic acid monoester represented by the formula (I-1-2) or (I-1-3), monomethyl itaconate, monoethyl itaconate, mono-n-propyl itaconate, mono-n-butyl itaconate, mono-n-pentyl itaconate, mono-n-hexyl itaconate, mono-n-heptyl itaconate, mono-n-octyl itaconate, mono-n-nonyl itaconate, mono-n-decyl itaconate, mono-n-undecylitaconate, mono-n-dodecyl itaconate (laurylitaconate), mono-n-tetradecyl itaconate, mono-n-hexadecyl itaconate, mono-n-octadecyl itaconate or the like, preferably monomethyl itaconate, monoethyl itaconate, mono-n-propyl itaconate, mono-n-butyl itaconate, mono-n-octyl itaconate, mono-n-decyl itaconate, mono-n-dodecyl itaconate (laurylitaconate), mono-n-octadecyl itaconate or a similar compound, and preferably mono-n-butyl itaconate, mono-n-pentyl itaconate, mono-n-octyl itaconate, mono-n-nonyl itaconate, mono-n-decyl itaconate.

[0114] Particularly preferably, when R is an isomeric alkyl group, as the maleic acid monoester represented by the formula (I-1-1), monoisopropyl maleate, monoisobutyl maleate, mono-sec-butyl maleate, mono-tert-butyl maleate, monoisoamyl maleate, monoisohexyl maleate, monoisooctyl maleate (mono-2-ethylhexyl maleate), monoisononyl maleate, monoisodecyl maleate, monoisoundecyl maleate, monoisododecyl maleate, monoisotridecyl maleate, monoisotetradecyl maleate, monoisopentadecyl maleate, monoisoheptadecyl maleate or the like can be selected, preferably monoisopropyl maleate, monoisobutyl maleate, mono-sec-butyl maleate, monoisooctyl maleate, monoisononyl maleate, monoisodecyl maleate, monoisoundecyl maleate, monoisotridecyl maleate, monoisooctadecyl maleate or the like, and preferably mono-tert-butyl maleate, mono-sec-butyl maleate, monoisoamyl maleate, monoisooctyl maleate (mono-2-ethylhexyl maleate), monoisononyl maleate, monoisoundecyl maleate, monoisotridecyl maleate;as the itaconic acid monoester represented by the formula (I-1-2) or (I-1-3), monoisopropyl itaconate, monoisobutyl itaconate, mono-sec-butyl itaconate, mono-tert-butyl itaconate, monoisoamyl itaconate, monoisohexylitaconate, monoisooctyl itaconate (mono-2-ethylhexylitaconate), monoisononyl itaconate, monoisodecyl itaconate, monoisoundecyl itaconate, monoisotridecyl itaconate or the like can be selected, preferably monoisopropyl itaconate, monoisobutyl itaconate, monoisooctyl itaconate (mono-2-ethylhexylitaconate), monoisononyl itaconate, monoisodecyl itaconate, monoisoundecyl itaconate, monoisostearyl itaconate or the like, and more preferably mono-tert-butyl itaconate, monoisoamyl itaconate, monoisohexylitaconate, monoisooctylitaconate (mono-2-ethylhexylitaconate), monoisononylitaconate, monoisoundecylitaconate;

[0115] It is particularly preferable when R is an unsaturated linear or branched aliphatic hydrocarbyl group, as the maleic acid monoester of the formula (I-1-1), mono allyl maleate, mono-3-butene-1-ol maleate, monoisopropenyl maleate, mono-3-hexen-1-ol maleate, mono-1-hepten-3-ol maleate, monomethylheptenyl maleate, mono-2-octen-1-ol maleate, mono-3-nonen-1-ol maleate, mono-2-decen-1-ol maleate, mono-7-dodecen-1-ol maleate, mono-1,5-hexadienol maleate, mono-2,4-nonadien-1-ol maleate, mono-2,4-decadien-1-ol maleate, mono-9,11-dodecadienol maleate, monooleyl maleate or the like, preferably monoallyl maleate, mono-3-buten-1-ol maleate, monoisopropenyl maleate, mono-3-hexen-1-ol maleate, mono-1-hepten-3-ol maleate, monomethylheptenyl maleate, mono-3-nonen-1-ol maleate, mono-2,4-decadien-1-ol maleate, monooleyl maleate or the like, and more preferably mono-2-octen-1-ol maleate, mono-3-nonen-1-ol maleate, mono-2-decen-1-ol maleate,monooleyl maleate or a similar compound; as the itaconic acid monoester represented by the formula (I-1-2) or (I-1-3), monoallylitaconate, mono-2-butene-1-olitaconate, mono-3-butene-1-olitaconate, mono-isopropenylitaconate, mono-3-hexene-1-olitaconate, mono-1-heptene-3-olitaconate, monomethylheptenylitaconate, mono-2-octene-1-olitaconate, mono-3-nonene-1-olitaconate, mono-2-decene-1-olitaconate, mono-7-dodecene-1-olitaconate, mono-1,5-hexadienolitaconate, mono-2,4-nonadiene-1-olitaconate, mono-2,4-decadienolitaconate, mono-9,11-dodecadienolitaconate can be selected, monooleyl itaconate or the like, preferably mono-allyl itaconate, mono-3-butene-1-olitaconate, mono-isopropenyl itaconate, mono-3-hexene-1-olitaconate, mono-3-nonene-1-olitaconate, monooleyl itaconate or the like, and more preferably mono-2-octene-1-olitaconate, mono-3-nonene-1-olitaconate, monooleyl itaconate.

[0116] It is particularly preferable that when R is an alicyclic hydrocarbyl group, as the maleic acid monoester represented by the formula (I-1-1), monocyclobutyl maleate, monocyclopentyl maleate, monocyclohexyl maleate, mono-3-cyclohexene-1-methyl maleate, mono-2-cyclohexenyl maleate or the like can be selected; as the itaconic acid monoester represented by the formula (I-1-2) or (I-1-3), itaconic acid monocyclohexyl ester, itaconic acid mono-2-cyclohexenyl ester, etc. can be selected.

[0117] It is particularly preferable that when R is a hydrocarbyl-substituted aryl group, mono-p-nonylphenyl maleate, mono-p-dodecylphenyl maleate or the like can be selected as the maleic acid monoester represented by the formula (I-1-1); mono-p-nonylphenyl itaconate, mono-p-dodecylphenyl itaconate can be selected as the itaconic acid monoester represented by the formula (I-1-2) or (I-1-3).

[0118] It is particularly preferable that when R is an aryl-substituted hydrocarbyl group, monobenzyl maleate, monophenylethyl maleate, monophenylpropyl maleate can be selected as the maleic acid monoester represented by the formula (I-1-1); monobenzyl itaconate, monophenylethyl maleate, monophenylpropyl maleate can be selected as the itaconic acid monoester represented by the formula (I-1-2) or (I-1-3).

[0119] According to the present invention, the dicarboxylic acid monoester represented by the formula (I-2) is a dicarboxylic acid monoester which is formed by esterifying one carboxyl group of a saturated linear or branched dicarboxylic acid C 3-10 .

[0120] According to a further preferred embodiment, the dicarboxylic acid monoester represented by formula (I-2) is a saturated linear dicarboxylic acid monoester, i.e., a dicarboxylic acid monoester represented by formula (I-2) in which the carbon chain between two carbonyl groups is a saturated linear chain.

[0121] Particularly preferably, as the dicarboxylic acid monoester represented by the formula (I-2), malonic acid monoester, succinic acid monoester (i.e., succinic acid monoester), glutaric acid monoester, adipic acid monoester, pimelic acid monoester, suberic acid monoester, azelaic acid monoester, sebacic acid monoester, undecanedicarboxylic acid monoester, dodecanedioic acid monoester, tridecanedioic acid monoester, tetradecanedioic acid monoester, hexadecanedioic acid monoester, octadecanedicarboxylic acid monoester or the like can be selected.

[0122] Particularly preferably, as the dicarboxylic acid monoester represented by the formula (I-2), malonic acid monoester, succinic acid monoester, glutaric acid monoester, adipic acid monoester, azelaic acid monoester, and sebacic acid monoester can be selected.

[0123] As exemplary malonic acid monoesters, more preferable are monomethyl malonate, monoethyl malonate, monopropyl malonate, mono-n-butyl malonate, mono-n-hexyl malonate, mono-n-octyl malonate, mono-n-decyl malonate, mono-n-dodecyl malonate (lauryl ester), mono-isobutyl malonate, mono-tert-butyl malonate, mono-isooctyl malonate, mono-isononyl malonate, mono-isodecyl malonate, mono-isoundecyl malonate, mono-iso-tridecyl malonate, mono-oleyl malonate (mono-9-octadecenyl malonate), monocyclohexyl malonate, mono-3-cyclohexene-1-methyl malonate, mono-p-nonylphenyl malonate, mono-benzyl malonate or the like connection.

[0124] As exemplary monoesters of succinic acid, more preferable are mono-n-butyl succinate, mono-sec-butyl succinate, mono-n-hexyl succinate, mono-n-octyl succinate, mono-n-decyl succinate, mono-n-dodecyl succinate (lauryl ester), mono-isobutyl succinate, mono-tert-butyl succinate, mono-isoamyl succinate, mono-isohexyl succinate, mono-isooctyl succinate, mono-isononyl succinate, mono-isodecyl succinate, mono-isoundecyl succinate, mono-isotridecyl succinate, mono-oleyl succinate (mono-9-octadecenyl succinate), monocyclohexyl succinate, mono-3-cyclohexene-1-methyl succinate, mono-p-nonylphenyl succinate and mono-benzylsuccinate or the like.

[0125] As exemplary monoesters of glutaric acid, more preferable are mono methyl glutarate, mono ethyl glutarate, mono propyl glutarate, mono-n-butyl glutarate, mono-n-hexyl glutarate, mono-n-octyl glutarate, mono-n-decyl glutarate, mono-n-dodecyl glutarate (lauryl ester), mono-isobutyl glutarate, mono-tert-butyl glutarate, monoisooctyl glutarate, monoisononyl glutarate, monoisodecyl glutarate, monoisoundecyl glutarate, monoisotridecyl glutarate, monooleyl glutarate (mono-9-octadecenyl glutarate), monocyclohexyl glutarate, mono-3-cyclohexene-1-methyl glutarate, mono-p-nonylphenyl glutarate, monobenzyl glutarate or the like.

[0126] As exemplary monoesters of adipic acid, monomethyl adipate, monoethyl adipate, mono-n-butyl adipate, mono-n-hexyl adipate, mono-n-octyl adipate, mono-n-decyl adipate, mono-n-dodecyl adipate (lauryl ester), monopropyl adipate, monoisobutyl adipate, monoisooctyl adipate, monoisononyl adipate, monoisodecyl adipate, monoisoundecyl adipate, monoisotridecyl adipate, monooleyl adipate (mono-9-octadecenyl adipate), monocyclohexyl adipate, mono-3-cyclohexene-1-methyl adipate, mono-p-nonylphenyl adipate, monobenzyladipate or the like are more preferable.

[0127] As exemplary azelaic acid monoesters, more preferable are mono methyl azelainate, mono ethyl azelainate, mono propyl azelainate, mono-n-butyl azelainate, mono-n-hexyl azelainate, mono-n-octyl azelainate, mono-n-decyl azelainate, mono-n-dodecyl azelainate (lauryl ester), mono isobutyl azelainate, mono isooctyl azelainate, mono isononyl azelainate, mono isodecyl azelainate, mono isothridecyl azelainate, mono oleyl azelainate (mono-9-octadecenyl azelainate), mono cyclohexyl azelainate, mono-3-cyclohexene-1-methyl azelainate, mono-p-nonylphenyl azelainate, monobenzyl azelaic acid or a similar compound.

[0128] As exemplary sebacic acid monoesters, more preferred are monomethyl sebacate, monoethyl sebacate, monopropyl sebacate, mono-n-butyl sebacate, mono-n-hexyl sebacate, mono-n-octyl sebacate, mono-n-decyl sebacate, mono-n-dodecyl sebacate (lauryl ester), monoisobutyl sebacate, monoisooctyl sebacate, monoisononyl sebacate, monoisodecyl sebacate, monoisoundecyl sebacate, monoisotridecyl sebacate, monooleyl sebacate (mono-9-octadecenyl sebacate), monocyclohexyl sebacate, mono-3-cyclohexene-1-methyl sebacate, mono-p-nonylphenyl sebacate, monobenzyl sebacate or similar connection.

[0129] According to the present invention, a dicarboxylic acid monoester represented by the formula (I-3) is a dicarboxylic acid monoester obtained by esterifying one carboxyl group of a dicarboxylic acid C 5-12, containing an optionally substituted saturated or unsaturated carbon ring structure containing from 3 to 10 carbon atoms in the main chain. Preferably, m is 0, Q is a substituted or unsubstituted divalent alicyclic hydrocarbyl group C 4-8 or a substituted or unsubstituted divalent aryl group C 6-10 , and R is a hydrocarbyl group C 4-12 .

[0130] Particularly preferably, as the dicarboxylic acid monoester represented by the formula (I-3), there can be selected 1,2-cyclohexanedicarboxylic acid monoester, tetrahydrophthalic acid monoester (i.e., 4-cyclohexene-1,2-dicarboxylic acid monoester), phthalic acid monoester, terephthalic acid monoester, 3-methylhexahydrophthalic acid monoester (i.e., 3-methyl-1,2-cyclohexanedicarboxylic acid monoester), 4-methylhexahydrophthalic acid monoester (i.e., 4-methyl-1,2-cyclohexanedicarboxylic acid monoester), methylhexahydrophthalic acid monoester, methyltetrahydrophthalic acid monoester, 4-methyl-4-cyclohexene-1,2-dicarboxylic acid, 3-methyl-4-cyclohexene-1,2-dicarboxylic acid monoester or a similar compound.

[0131] Furthermore, particularly preferably, as the dicarboxylic acid monoester represented by the formula (I-3), 1,2-cyclohexanedicarboxylic acid monoester, tetrahydrophthalic acid monoester, phthalic acid monoester, methylhexahydrophthalic acid monoester and methyltetrahydrophthalic acid monoester can be selected, for example, 1,2-cyclohexanedicarboxylic acid butyl monoester, 1,2-cyclohexanedicarboxylic acid octyl monoester, 1,2-cyclohexanedicarboxylic acid isooctyl monoester, 1,2-cyclohexanedicarboxylic acid isononyl monoester, tetrahydrophthalic acid butyl monoester, tetrahydrophthalic acid octyl monoester, isooctyl monoester tetrahydrophthalic acid, isononyl tetrahydrophthalic acid monoester, butyl phthalic acid monoester, octyl phthalic acid monoester,isooctyl phthalic acid monoester, isononyl phthalic acid monoester, butyl methyl hexahydrophthalic acid monoester, octyl methyl hexahydrophthalic acid monoester, isooctyl methyl hexahydrophthalic acid monoester, isononyl methyl hexahydrophthalic acid monoester, lauryl methyl hexahydrophthalic acid monoester, butyl methyl tetrahydrophthalic acid monoester, octyl methyl tetrahydrophthalic acid monoester, isooctyl methyl tetrahydrophthalic acid monoester, isononyl methyl tetrahydrophthalic acid monoester, lauryl methyl tetrahydrophthalic acid monoester or the like.

[0132] According to some particularly preferred embodiments, monobutyl maleate, monoisooctyl maleate, monoisononyl maleate, monoisooctyl succinate, monohexyl phthalate, monoisooctyl phthalate, monoisooctyl methyl tetrahydrophthalate, monoisooctyl citraconate, monoisooctyl itaconate, mono-tert-butyl malonate can be selected as the dicarboxylic acid monoester represented by formula (I-1), (I-2) or (I-3). Most preferably, monobutyl maleate, monoisooctyl maleate, monoisononyl maleate, monoisooctyl itaconate, monoisooctyl succinate, monohexyl phthalate, monoisooctyl phthalate, monoisooctyl methyl tetrahydrophthalate, mono-tert-butyl malonate can be selected as the dicarboxylic acid monoester.

[0133] According to the present invention, a dicarboxylic acid monoester represented by the formula (I-1), (I-2) or (I-3) can be obtained by a reaction involving a saturated dicarboxylic acid, an unsaturated dicarboxylic acid, a cyclic dicarboxylic acid or a benzenedicarboxylic acid or anhydride of the corresponding acid and a C alcohol 3-20 or phenol. According to the reaction conditions, include: a dicarboxylic acid or anhydride and alcohol C 2-20 or phenol are reacted in a molar ratio of 1:0.5 to 1:1.5 at a temperature of 50 to 250°C for 0.1 to 10 hours, and the reaction pressure is atmospheric pressure or a specific pressure.

[0134] According to some further preferred embodiments, the dicarboxylic acid monoester of component A may be selected from dicarboxylic acid monoesters represented by formula (I-4):

[0135]

[0136] where R8 is a divalent hydrocarbyl group C 2-10 ; R9 represents a hydrogen atom or a hydrocarbyl group with or without a double bond, R 10 is a divalent hydrocarbyl group, with or without a double bond, and the total number of carbon atoms in the R9 and R groups 10 ranges from 15 to 21; R 11 represents a hydrogen atom or a hydrocarbyl group C 1-10 .

[0137] According to a further preferred embodiment, the total number of carbon atoms in the R9 and R groups 10 ranges from 15 to 21, and the total number of double bonds ranges from 0 to 3, such as each of the R9 and R groups 10 alkyl, alkenyl, dienyl, etc. can be independently selected.

[0138] According to a further preferred embodiment R 11represents a hydrogen atom or a hydrocarbyl group C 1-4 , which may include alkyl groups C 1-4 and alkenyl groups C 2-4 , such as methyl, ethyl, n-propyl, propenyl, n-butyl, isobutyl, butenyl and the like groups, most preferably hydrogen, methyl or ethyl.

[0139] According to a further preferred embodiment, R8 may be alkylene, alkenylene, alkyl-substituted alkylene, alkyl-substituted alkenylene, alkenyl-substituted alkylene, alkenyl-substituted alkenylene, cycloalkylene, alkyl-substituted cycloalkylene, alkenyl-substituted cycloalkylene, cyclo alkenylene, alkyl-substituted cycloalkenylene, alkenyl-substituted cycloalkenylene, arylene, alkyl-substituted arylene, or alkenyl-substituted arylene having 2 to 10 carbon atoms; the alkylene group may be a normal alkylene group or an isomeric alkylene group, and the alkenylene group may be a normal alkenylene group or an isomeric alkenylene group; more preferably, R8 is C alkylene 2-8 , alkenylene C 2-8 , alkyl- or alkenyl-substituted alkylene C 2-8 , alkyl- or alkenyl-substituted alkenylene C 2-8 , cycloalkylene C 3-8 , cycloalkenylene C 3-8, alkyl- or alkenyl-substituted cycloalkylene C 6-8 , alkyl- or alkenyl-substituted cycloalkenylene C 6-8 , arylene C 6-10 , alkyl- or alkenyl-substituted arylene C 7-10 such as ethylene, vinylene, methyleneethylene, methylethylene, butylene, methylbutylene, butenylene, phenylene, cyclohexylene, methylhexahydrophenylene, methyltetrahydrophenylene, etc.

[0140] According to the following preferred embodiment, in the structural formula (I-4), R8 is a divalent hydrocarbyl group C 2-8 ; R9 represents a hydrogen atom or a hydrocarbyl group, R 10 is a divalent hydrocarbyl group, and the total number of carbon atoms in the R9 and R groups 10 ranges from 15 to 21, and the total number of double bonds between carbon atoms ranges from 0 to 3; R 11 represents a hydrogen atom or a hydrocarbyl group C 1-4 .

[0141] According to the present invention, a dicarboxylic acid monoester represented by the formula (I-4) can be obtained by an esterification reaction involving a fatty hydroxy acid and / or a fatty hydroxy acid ester (for short, referred to as "fatty hydroxy acid (ester)") and a dicarboxylic acid and / or anhydride of the corresponding acid. The esterification reaction can be carried out under the following conditions: a temperature in the range of 30 to 300°C, preferably 50 to 250°C, and more preferably 70 to 180°C; a reaction time of 30 minutes to 30 hours, preferably 2 to 20 hours, and more preferably 4 to 10 hours.The esterification reaction is optionally carried out in the presence of a solvent, which may be toluene, xylene, ethylbenzene, petroleum ether, solvent oil, cyclohexane, n-octane or mixtures thereof, and a catalyst, which may be an acid catalyst such as sulfuric acid, p-toluenesulfonic acid, phosphoric acid, boric acid, etc.

[0142] As an example, hydroxyoctadecanoic acid (hydroxystearic acid), hydroxyoctadecenoic acid (ricinoleic acid), hydroxyoctadecadienoic acid, hydroxydocosanoic acid, hydroxydocosenoic acid, hydroxytetracosanoic acid, hydroxytetracosenoic acid or the like can be selected as the hydroxy fatty acid, preferably ricinoleic acid, hydroxystearic acid and hydroxyoctadecadienoic acid.

[0143] As an example, methyl hydroxyoctadecanoate (methyl hydroxystearate), methyl hydroxyoctadecenoate (methyl ricinoleate), ethyl ricinoleate, methyl hydroxyoctadecadienoate, methyl hydroxydocosanoate, methyl hydroxydocosenoate, methyl hydroxytetracosanoate, methyl hydroxytetracosenoate or the like can be selected as the hydroxy fatty acid ester, preferably methyl ricinoleate, methyl trans ricinoleate, ethyl ricinoleate and methyl hydroxyoctadecadienoate.

[0144] As an example, the dicarboxylic acid may be a saturated dicarboxylic acid, for example, one or more saturated dicarboxylic acids, which may be selected from succinic acid (1,4-butanedicarboxylic acid), glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid or the like; preferably, succinic acid, methylsuccinic acid, dimethylsuccinic acid, octysuccinic acid may be selected as the one or more saturated dicarboxylic acids.

[0145] Alternatively, the dicarboxylic acid may be an unsaturated dicarboxylic acid, such as cis-butenedicarboxylic acid (maleic acid), trans-butenedicarboxylic acid (fumaric acid), cis-methylbutenedicarboxylic acid (citraconic acid), trans-methylbutenedicarboxylic acid (mesaconic acid), dimethylmaleic acid, itaconic acid (methylenesuccinic acid, methylenebutanedicarboxylic acid), glutaconic acid, trans-3-hexenedicarboxylic acid, butynedicarboxylic acid, 2-butene-1,4-dicarboxylic acid, hexadienedicarboxylic acid, heptenedicarboxylic acid, octenedicarboxylic acid, nonenedicarboxylic acid, decenedicarboxylic acid, sebacenedicarboxylic acid, undecenedicarboxylic acid, dodecenedicarboxylic acid or a similar compound;in addition, one or more dicarboxylic acids may be present, which may be selected from pentenylsuccinic acid, hexadienylsuccinic acid, heptenylsuccinic acid, octenylsuccinic acid, nonenylsuccinic acid, decenylsuccinic acid or the like, and preferably one or more dicarboxylic acids may be present, which may be selected from cis-butenedicarboxylic acid (maleic acid), trans-butenedicarboxylic acid (fumaric acid), cis-methylbutenedicarboxylic acid (citraconic acid), trans-methylbutenedicarboxylic acid (mesaconic acid), dimethylmaleic acid, itaconic acid (methylenesuccinic acid, methylenebutanedicarboxylic acid), 2-butene-1,4-dicarboxylic acid, decenylsuccinic acid or the like;

[0146] As an example, as the saturated dicarboxylic acid anhydride, butanedicarboxylic anhydride (succinic anhydride), glutaric anhydride, adipic anhydride, phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, methyl tetrahydrophthalic anhydride or the like can be selected;in addition, one or more anhydrides may be present, which are methylglutaric anhydride, methylsuccinic anhydride, dimethylsuccinic anhydride, ethylsuccinic anhydride, propylsuccinic anhydride, butylsuccinic anhydride, pentylsuccinic anhydride, hexylsuccinic anhydride, heptylsuccinic anhydride, octylsuccinic anhydride, nonylsuccinic anhydride, decylsuccinic anhydride or the like, preferably one or more anhydrides, which can be selected as cis-butenedicarboxylic anhydride (maleic anhydride), 2,3-dimethylmaleic anhydride, citraconic anhydride, itaconic anhydride, glutaconic anhydride or the like.

[0147] As exemplary anhydrides of unsaturated dicarboxylic acids, one or more anhydrides can be selected that are (2-methyl-2-propenyl)succinic anhydride, vinyl succinic anhydride, propenyl succinic anhydride, butenyl succinic anhydride, triisobutenyl succinic anhydride, pentenyl succinic anhydride, 3-methyl-hexenylsuccinic anhydride, heptenyl succinic anhydride, octenyl succinic anhydride, nonenylsuccinic anhydride, decenyl succinic anhydride or the like.

[0148] The dicarboxylic acid anhydride is particularly preferably one or more anhydrides, which can be selected from maleic anhydride, citraconic anhydride, itaconic anhydride, succinic anhydride, glutaric anhydride, phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, methyl succinic anhydride, dimethyl succinic anhydride, nonyl succinic anhydride, decyl succinic anhydride, noneny succinic anhydride, decenyl succinic anhydride or the like.

[0149] According to a particularly preferred embodiment, the dicarboxylic acid monoester compound represented by the formula (I-4) may be selected from the group consisting of maleic acid monoester-substituted methyl ricinoleate, maleic acid ester-substituted ricinoleic acid, succinic acid monoester-substituted methyl ricinoleate, succinic acid monoester-substituted ricinoleic acid, succinic acid monoester-substituted methyl 12-hydroxystearate, maleic acid monoester-substituted methyl 12-hydroxystearate, phthalic acid monoester-substituted methyl ricinoleate, methyl hexahydrophthalic acid monoester-substituted methyl ricinoleate, methyl tetrahydrophthalic acid monoester-substituted methyl ricinoleate and their combinations.

[0150] Component B

[0151] According to the present invention, component B is a long-chain fatty acid C8-24 , an ester of a polyhydric alcohol and a long-chain fatty acid C 8-24 or mixtures thereof.

[0152] As an example, as a long-chain fatty acid C 8-24 Caprylic acid, capric acid, lauric acid (dodecanoic acid), myristic acid (tetradecanoic acid), palmitic acid (hexadecanoic acid), palmitoleic acid (hexadecenoic acid), stearic acid (octadecanoic acid), oleic acid (octadecenoic acid), linoleic acid (octadecadienoic acid), linolenic acid (octadecatrienoic acid), ricinoleic acid (hydroxyoctadecenoic acid), hydroxystearic acid, arachidic acid (eicosanoic acid), arachidonic acid (eicosenoic acid), behenic acid (docosanoic acid), erucic acid (docosenoic acid) or a similar compound, as well as mixtures thereof, can be selected.

[0153] According to a preferred embodiment, unsaturated fatty acids C can be selected as component B 12-20 , esters of polyhydric alcohols and unsaturated fatty acids C 12-20 or mixtures thereof.

[0154] As an example, as an unsaturated fatty acid C 12-20 oleic acid, linoleic acid, linolenic acid, ricinoleic acid or combinations thereof may be preferably selected, or fatty acid mixtures containing oleic acid, linoleic acid, linolenic acid, and ricinoleic acid as the main ingredient may be selected.

[0155] Natural oil or waste oil can be hydrolyzed to produce various fatty acid mixtures and converted into unsaturated fatty acid products through distillation or urea addition, low-temperature freeze crystallization. Biodiesel can also be converted into unsaturated fatty acids through hydrolysis. After distillation or urea addition, low-temperature freeze crystallization is used. Tall oil fatty acids obtained from the paper industry contain a large amount of unsaturated fatty acids. All of these products constitute the preferred component B.A mixture of unsaturated fatty acids obtained by hydrolyzing and refining tall oil, cottonseed oil, acidified cottonseed oil, soybean oil, acidified soybean oil or the like used as raw materials is also a preferred component B, and relevant examples are unsaturated fatty acid JC2006S supplied by Jiangsu Chuangxin Petrochemical Co., Ltd., unsaturated fatty acid KMJ-031 supplied by Xinjiang Dasen Chemical Co., Ltd., and unsaturated fatty acid R90 supplied by Jiangxi Xilinke Co., Ltd., and the like.

[0156] According to the present invention, the ester of a polyhydric alcohol and a long-chain fatty acid means various esterification products such as mono-, di- and triesters, as well as mixtures thereof, obtained as a result of esterification in which the above-mentioned long-chain saturated or unsaturated fatty acids and polyhydric alcohols participate.

[0157] As an example, the polyhydric alcohol may be, but is not limited to, ethylene glycol, glycerin, 1,2-propanediol, 1,3-propanediol, sorbitan, pentaerythritol, trimethylolpropane or the like, with glycerin being preferred.

[0158] According to a preferred embodiment, the polyhydric alcohol ester is a glycerol ester, which can be preferably selected from monoglycerides and diglycerides, and more preferably monoglycerides of unsaturated fatty acids, which can be most preferably selected from monoglycerol oleate, monoglycerol linoleate, monoglycerol linolenate, monoglycerol ricinoleate. It is preferable to use component B, which is a glyceride obtained by esterifying an unsaturated fatty acid with glycerol, such as JC-2017Z supplied by Jiangsu Chuangxin Petrochemical Co., Ltd. or the like.

[0159] According to the second aspect, a method for producing a composition for improving the lubricity of diesel fuel according to the present invention is provided, in which component A and component B are uniformly mixed in a weight ratio of from 9:1 to 1:9, preferably from 7:3 to 3:7, and more preferably from 6:4 to 4:6.

[0160] According to a third aspect of the present invention, a method is provided for improving the lubricity of diesel fuel, comprising adding to low-sulfur diesel fuel a composition for improving the lubricity of diesel fuel according to the present invention, wherein the composition for improving the lubricity of diesel fuel is added in an amount of preferably from 10 to 400 parts per million and more preferably from 50 to 200 parts per million relative to the weight of low-sulfur diesel fuel.

[0161] According to a fourth aspect of the present invention, there is provided a diesel fuel composition comprising a low-sulfur diesel fuel and a composition for improving the lubricity of diesel fuel according to the present invention, wherein the composition for improving the lubricity of diesel fuel is present in the diesel fuel composition in an amount of preferably from 10 to 400 parts per million and more preferably from 50 to 200 parts per million relative to the weight of the low-sulfur diesel fuel.

[0162] The low-sulfur diesel fuel suitable for use with the lubricity improving composition of the present invention is a variety of low-sulfur diesel fuel. For example, the diesel fuel may be a fuel for compression ignition internal combustion engines that meets the national standard GB / T19147 for automotive diesel fuel, and which is obtained by processing crude feedstock (oil) through various refining processes in a refinery, such as atmospheric and vacuum distillation, catalytic cracking, catalytic reforming, coking, hydrotreating, hydrocracking and the like, to obtain a fraction having a distillation range of 160°C to 380°C, followed by blending.

[0163] Low sulfur diesel fuel may also be a second-generation biodiesel fuel that is produced from renewable resources such as vegetable oils and animal fats, and which is typically produced by hydrogenating vegetable oils to produce isomerized or non-isomerized long-chain hydrocarbons using a hydroprocessing process that is commonly used in petroleum refineries, and this fuel may be similar in nature and quality to petroleum-based diesel fuel.

[0164] In addition, low-sulfur diesel fuel can be a third-generation biodiesel fuel, which is produced by processing non-petroleum-based biomass with high cellulose content, such as sawdust, straw, solid waste and similar materials, and microbial oil using gasification and Fischer-Tropsch technology.

[0165] Low-sulfur diesel fuel may also be coal-liquefied diesel fuel (CTL), which refers to coal-based diesel fuel produced by Fischer-Tropsch synthesis or coal-based diesel fuel produced by direct liquefaction. It may also be a blended diesel fuel produced by adding an oxygenated diesel blending component to petroleum-based diesel fuel, wherein the oxygenated diesel blending component is an oxygen-containing compound or mixtures of oxygenated compounds that can be blended with various types of diesel fuel to meet specific specifications and requirements, and is typically alcohols and ethers or mixtures thereof, such as ethanol, polyoxymethylene dimethyl ethers (PODEn, DMMn, or OME for short), and similar materials.

[0166] The diesel fuel composition according to the present invention may further contain other additives, such as one or more of the following materials: phenolic antioxidants, polymeric amine ashless dispersants, flow improvers, cetane improvers, metal deactivators, antistatic agents, corrosion inhibitors, rust inhibitors, demulsifying agents in accordance with the requirements

[0167] Examples

[0168] The present invention will now be illustrated in detail by presenting the following examples, but it should not be construed as being limited to these examples.

[0169] In the following Examples and Comparative Examples, the reagents and starting materials used are commercially available chemically pure materials unless otherwise specified.

[0170] In the following Examples and Comparative Examples, the infrared spectrum of the obtained product was recorded using a Nicolet iS50 Fourier transform infrared spectrometer from Thermo Fisher Scientific.

[0171] In the following examples and comparative examples, the composition analysis of the obtained product was performed using an Agilent 7890A-5975C GC-MS chromatograph under the following chromatographic conditions: initial temperature of 50°C, heating rate of 5°C / min, column temperature of 300°C, flame ionization detector (FID), area normalization method for quantification, and HP-5 chromatographic column.

[0172] In the following examples and comparative examples, photographs of wear scars for diesel fuel before and after adding a lubricity improving composition were taken to measure the wear scar diameter (WSD) at a temperature of 60°C using a high frequency reciprocating motion (HFRR) apparatus of PCS Instruments (United Kingdom) using the method in accordance with the SH / T 0765 standard.

[0173] Preparation of a dicarboxylic acid monoester

[0174] Preparative Example 1. Monoisononyl maleate

[0175] Into a 2000 ml reactor equipped with an electric stirrer and a thermometer, 490 g of maleic anhydride (cis-butenedicarboxylic anhydride, 99.5% by weight, manufactured by Zibo Qixiang Tengda Chemical Co., Ltd.) and 720 g of isomeric nonanol (Exxal™ 9s, 99.5% by weight, manufactured by Exxon-Mobil Co., Ltd.) were charged, and the molar ratio of maleic anhydride to isomeric nonanol was approximately 1:1, the mixture was heated to 85°C while stirring, the temperature was increased to 150°C after 5 hours of reaction, and the unreacted isomeric nonanol and maleic anhydride were removed by distillation under reduced pressure to obtain 1006 g of a product. The infrared spectrum of the obtained product is shown in Fig. 1, wherein the content of monoisononyl maleate is approximately 90.5%, and the content of diisononyl maleate is approximately 8.6%, according to gas chromatography coupled with mass spectrometry (GC-MS) analysis.

[0176] Preparative Example 2. Monoisooctyl succinate

[0177] Into a 2000ml reactor equipped with an electric stirrer, a thermometer and a reflux condenser, 490g of succinic anhydride (butanedicarboxylic anhydride, 99% by weight, manufactured by Shanghai Shenren Fine Chemical Co., Ltd.) and 700g of isooctanoic acid (2-ethylhexanol, 99.9% by weight, manufactured by Sinopec Qilu Petrochemical Company) were charged, and the molar ratio of succinic anhydride to isooctanoic acid was approximately 1:1.1, the mixture was heated to 110°C while stirring, after 4 hours of reaction, the temperature was raised to 160°C, and the unreacted isooctanoic acid was removed by distillation under reduced pressure to obtain 1109g of a product. The monoisooctyl succinate content is approximately 86.7% as analyzed by GC-MS.

[0178] Preparative Example 3. Monoisooctylmethyltetrahydrophthalate

[0179] In a 500ml reactor equipped with an electric stirrer and a thermometer, 166g of methyltetrahydrophthalic anhydride (98% by weight, manufactured by Shandong Yousheng Chemical Co., Ltd.) and 143g of isooctanoic acid (99.5% by weight, manufactured by Sinopec Qilu Petrochemical Company) were charged, and the molar ratio of methyltetrahydrophthalic anhydride to isooctanoic acid was approximately 1:1.1, the mixture was heated to 110°C with stirring, after 3.5 hours of reaction, the temperature was raised to 165°C, and the unreacted starting materials were removed by distillation under reduced pressure to obtain 243g of product. The content of monoisooctylmethyltetrahydrophthalate was approximately 85% according to GC-MS analysis.

[0180] Preparative Example 4. Monoisooctyl citraconate

[0181] Into a 500ml reactor equipped with an electric stirrer, a thermometer and a reflux condenser, 112g of methylmaleic anhydride (citraconic anhydride, analytical grade, manufactured by Shanghai Aladdin Biochemical Technology Co., Ltd.) and 143g of isooctanoic acid (2-ethylhexanol, 99.9% by weight, manufactured by Sinopec Qilu Petrochemical Company) were charged, and the molar ratio of methylmaleic anhydride to isooctanoic acid was approximately 1:1.1, the mixture was heated to 90°C while stirring, the temperature was increased to 140°C after 4 hours of reaction, and the unreacted isooctanoic acid was removed by distillation under reduced pressure to obtain 245g of a product mainly containing monoisooctyl citraconate.

[0182] Preparative Example 5. Monoisooctyldodecenylsuccinate

[0183] In a 500ml reactor equipped with an electric stirrer, a thermometer and a reflux condenser, 200g of dodecenyl succinic anhydride (analytical grade, manufactured by Beijing Yinokai Technology Co., Ltd.) and 117g of isooctanoic acid (2-ethylhexanol, 99.9% by weight, manufactured by Sinopec Qilu Petrochemical Company) were charged, and the molar ratio of dodecenyl succinic anhydride to isooctanoic acid was approximately 1:1.2, the mixture was heated to 100°C while stirring, the temperature was increased to 150°C after 3 hours of reaction, and the unreacted isooctanoic acid was removed by distillation under reduced pressure to obtain 303g of a product mainly containing monoisooctyl dodecenyl succinate.

[0184] Preparative Example 6. Maleic acid monoester-substituted methyl ricinoleate

[0185] In a 500 ml reactor equipped with an electric stirrer, a thermometer and a reflux condenser, 350.5 g of methyl ricinoleate (75% by weight, manufactured by Shanghai Aladdin Biochemical Technology Co., Ltd.) and 100 g of maleic anhydride (cis-butenedicarboxylic anhydride, 99% by weight, manufactured by Shanghai Aladdin Biochemical Technology Co., Ltd.) were charged, and the molar ratio of methyl ricinoleate to maleic anhydride was approximately 1.1:1, the mixture was heated to 100°C while stirring, and the reaction was carried out for 3 hours to obtain 442.7 g of a product mainly containing maleic acid monoester substituted methyl ricinoleate, and the content of maleic acid monoester substituted methyl ricinoleate was approximately 88% according to GC-MS analysis.

[0186] The reaction scheme is shown in the following equation 1.

[0187]

[0188] Preparative Example 7. Monoisooctyl itaconate

[0189] Into a 500ml reactor equipped with an electric stirrer, a thermometer and a reflux condenser, 200g of methylene succinic anhydride (itaconic anhydride, analytical grade, manufactured by Beijing Yinokai Technology Co., Ltd.) and 240.3g of isooctanoic acid (2-ethylhexanol, 99.9% by weight, manufactured by Sinopec Qilu Petrochemical Company) were charged, and the molar ratio of methylene succinic anhydride to isooctanoic acid was approximately 1:1.2, the mixture was heated to 100°C while stirring, the temperature was increased to 140°C after 3 hours of reaction, and the unreacted raw materials were removed by distillation under reduced pressure to obtain 429.7g of a product mainly containing monoisooctyl itaconate. The monoisooctyl itaconate content is approximately 84% as analyzed by GC-MS.

[0190] Preparative Example 8. Monobenzyl maleate

[0191] Into a 500ml reactor equipped with an electric stirrer, a thermometer and a reflux condenser, 150g of maleic anhydride (cis-butenedicarboxylic anhydride, analytical grade, manufactured by Beijing Yinokai Technology Co., Ltd.) and 198.5g of benzyl alcohol (99% by weight, manufactured by Beijing Yinokai Technology Co., Ltd.) were charged, and the molar ratio of maleic anhydride to benzyl alcohol was approximately 1:1.2, the mixture was heated to 80°C while stirring, the temperature was raised to 150°C after 5 hours of reaction, and the unreacted raw materials were removed by distillation under reduced pressure to obtain 343.6g of a product mainly containing monobenzyl maleate. The monobenzyl maleate content is approximately 88% as analyzed by GC-MS.

[0192] Preparative Example 9. Methyl ricinoleate substituted with methyl tetrahydrophthalic acid monoester

[0193] Into a 500 ml reactor equipped with an electric stirrer, a thermometer and a reflux condenser, 248 g of methyl ricinoleate (75% by weight, manufactured by Shanghai Arlatin Biochemical Technology Co., Ltd.) and 100 g of methyl tetrahydrophthalic anhydride (99% by weight, manufactured by Beijing Yinokai Technology Co., Ltd.) were charged, and the molar ratio of methyl ricinoleate to methyl tetrahydrophthalic anhydride was approximately 1.1, and the mixture was heated to 140°C while stirring, and a reaction was carried out for 3 hours to obtain 329.1 g of a product mainly containing methyl ricinoleate substituted with methyl tetrahydrophthalic acid monoester. The content of methyl ricinoleate, a substituted monoester of methyl tetrahydrophthalic acid, is approximately 77% according to GC-MS analysis.

[0194] Example compositions for improving lubricity

[0195] The lubricity improving compositions in Examples 1 to 32 and Comparative Examples 1 to 5 were obtained by uniformly mixing Component A and Component B in accordance with the compositions and mass ratios shown in Tables 1-1 to 1-3.

[0196]

[0197]

[0198] Table 1-1 shows Examples 1-2 and Comparative Examples 1-3 to illustrate the improvement in the performance of the lubricity-improving compositions of the present invention compared with the lubricity-improving compositions that do not conform to the present invention; Examples 3-5 are shown to illustrate the effect of selecting Component A on the performance of the lubricity-improving compositions of the present invention when Component B is an ester of a polyhydric alcohol and a long-chain fatty acid; Examples 5-8 are shown to illustrate the effect of selecting the weight ratio of Components A and B on the performance of the lubricity-improving compositions of the present invention when Component B is an ester of a polyhydric alcohol and a long-chain fatty acid.

[0199]

[0200]

[0201] Table 1-2 provides Examples 9-14 to illustrate the effect of selecting Component A on the performance of the lubricity-improving compositions of the present invention when Component B is a long-chain fatty acid; Examples 14-21 and Comparative Examples 4-5 are provided to illustrate the effect of selecting the weight ratio of Components A and B on the performance of the resulting lubricity-improving composition when Component B is a long-chain fatty acid.

[0202]

[0203]

[0204] Table 1-3 shows Examples 22-32 to illustrate the performance characteristics of other lubricity improving compositions according to the present invention obtained by mixing component A and component B.

[0205] The details of the commercially available component A used in Examples 1-32 are as follows:

[0206] Monoisooctyl maleate: Manufacturer TCI Shanghai Chemical Industry Development Co., Ltd., purity 95%;

[0207] Diisooctyl maleate: manufacturer Beijing Yinokai Technology Co., Ltd., purity 95%;

[0208] Mono-tert-butyl malonate:manufactured by Ark Pharm Corporation, purity above 97%; Mono-n-butyl maleate:manufactured by Hubei Jusheng Technology Co., Ltd., purity 99%; and

[0209] Monohexyl phthalate: Manufacturer Shanghai Aladdin Biochemical Technology Co., Ltd., purity 98%.

[0210] As the component A used in Examples 1 to 32, the compounds of the formula (I-1) are mono-n-butyl maleate (see particularly Example 30), monoisononyl maleate (see particularly Example 27), monoisooctyl citraconate (see particularly Example 22) and the like; the compounds of the formula (I-2) are mono-tert-butyl malonate (see particularly Example 29) and the like; the compounds of the formula (I-3) are monohexyl phthalate (see particularly Example 32), monoisooctyl methyl tetrahydrophthalate (see particularly Example 24) and the like; the compounds of the formula (1-4) are maleic acid monoester-substituted methyl ricinoleate (see particularly Example 13) and the like.

[0211] The details of the commercially available component B used in Examples 1-32 are as follows:

[0212] Linoleic acid: Manufacturer Shanghai Aladdin Biochemical Technology Co., Ltd., purity 95%;

[0213] Oleic acid: Manufacturer Shanghai Aladdin Biochemical Technology Co., Ltd., analytical grade reagent;

[0214] tall oil fatty acid 2LT: a mixture of fatty acids obtained by refining tall oil and containing mainly unsaturated fatty acids such as linoleic acid and oleic acid, manufactured by Arizonal Corporation (USA);

[0215] Unsaturated fatty acids KMJ-031, JC-2006S and R90: are mainly linoleic acid and oleic acid, the detailed information of which is shown in Table 2;

[0216] Unsaturated fatty acid glycerides JC-2017Z: are mainly monoglycerides and diglycerides obtained by esterification of linoleic acid and oleic acid with glycerol, the detailed information of which is shown in Table 2.

[0217]

[0218]

[0219] Research Examples

[0220] The lubricity-improving compositions in Examples 1–32 and Comparative Examples 1–5 were mixed with diesel fuel, respectively, and their effects in diesel fuel were studied. Low-sulfur diesel fuel A is produced by Sinopec Yanshan Petrochemical Company, and ultra-low-sulfur diesel fuel B is produced by Sinopec Shanghai Gaoqiao Petrochemical Co., Ltd. The physicochemical properties of diesel fuel A and diesel fuel B are presented in Table 3.

[0221]

[0222]

[0223] The lubricity of diesel fuel was evaluated by measuring the wear scar diameter (WSD) at 60°C using a high frequency reciprocating motion (HFRR) apparatus from PCS Instruments (United Kingdom) according to the method of SH / T 0765, correcting for the effects of temperature and humidity, to obtain a final wear scar diameter change of WS1.4.

[0224] The wear scar diameter values ​​of WS1.4 diesel fuel before and after adding the lubricity improving composition are shown in Tables 4-1, 4-2, 5-1, 5-2, 5-3 and 5-4, wherein a smaller wear scar diameter indicates improved lubricity of diesel fuel. Currently, most diesel fuel standards in the world, such as the European standard EN 590, the national standard of the People's Republic of China GB 19147 for automotive diesel fuel and the Beijing local standard DB 11 / 239 for automotive diesel fuel, provide a standard wear scar diameter of less than 460 μm (60 °C) as the acceptance criterion for the lubricity of diesel fuel.

[0225]

[0226] As can be seen from the results shown in Table 4-1, the original diesel fuel A has a wear scar diameter WS1.4 of 564 μm (see the wear scar photograph in Fig. 2), and does not meet the performance requirements of automotive diesel fuel. The wear scar diameter WS1.4 of diesel fuel A decreases from 564 μm to 324 μm by individually applying 100 mg / kg of monoisooctyl maleate, decreases from 564 μm to 458 μm by individually applying 100 mg / kg of linoleic acid, and unexpectedly decreases from 564 μm to 226 μm by applying 100 mg / kg of the composition obtained in Example 1 by mixing monoisooctyl maleate and linoleic acid at a weight ratio of 7:3 (see the wear scar photograph in Fig. 3). In addition, even if the amount of the composition obtained in Example 1 is reduced to 70 mg / kg, the wear scar diameter of WS1.4 diesel fuel A can still be reduced from 564 μm to 305 μm (see(Fig. 4, a photograph of a wear scar). The above results clearly demonstrate that the lubricity-improving compositions of the present invention exhibit a significant synergistic effect between component A and component B, such that the lubricity-improving effect of the compositions significantly exceeds the respective individual effects of component A and component B, and as a result, the amount of the lubricity-improving composition used can be significantly reduced. On the other hand, the composition of Comparative Example 1, obtained by mixing diisooctyl maleate and linoleic acid in the same weight ratio, exhibits an unsatisfactory lubricity-improving effect and does not exhibit any synergistic effect.

[0227]

[0228] As can be seen from the results shown in Table 4-2, the original diesel fuel A shows a wear scar diameter of 564 μm, after individually adding 100 mg / kg diisooctyl maleate to the fuel, the modified diesel fuel shows a WS1.4 value of 561 μm, without showing any effect of improving the lubricity; after individually adding 100 mg / kg monoisooctyl maleate to the fuel, the modified diesel fuel shows a WS1.4 value of 324 μm (as shown in Table 4-1); meanwhile, after individually adding 100 mg / kg unsaturated fatty acid glyceride JC-2017Z to the fuel, the modified diesel fuel shows a WS1.4 value of 469 μm, which still does not meet the performance requirements.However, the composition obtained in Example 2 by mixing monoisooctyl maleate and the unsaturated fatty acid glyceride JC-2017Z at a weight ratio of 5:5 can reduce the WS1.4 value of the modified diesel fuel to 212 μm when added in an amount of 100 mg / kg, demonstrating an unexpected effect of improving the lubricity, and can reduce the WS1.4 value of the modified diesel fuel to 415 μm even when added in an amount of 50 mg / kg, while still satisfying the performance requirements. On the other hand, the effect of improving the lubricity of the composition obtained in Comparative Example 2 using diisooctyl maleate and the composition obtained in Comparative Example 3 using monoisooctyl dodecenyl succinate is significantly smaller than the corresponding effect of the composition of Example 2.

[0229]

[0230] As can be seen from the results shown in Table 5-1, the wear scar diameter WS1.4 of the original diesel fuel B is 651 μm (see Fig. 5 for a photograph of the wear scar diameter), which does not meet the performance requirements of automotive diesel fuel. After individually adding 100 mg / kg of monoisooctyl maleate, the WS1.4 value of the modified diesel fuel is 466 μm, which still does not meet the performance requirements; after individually adding 100 mg / kg of linoleic acid, the WS1.4 value of the modified diesel fuel is 513 μm. When the composition obtained in Example 1 of the present invention is added to diesel fuel in an amount of 100 mg / kg, the WS1.4 value of the modified diesel fuel decreases to 256 μm (see Fig.6 wear scar photograph), and when the composition is added to diesel fuel in an amount of 200 mg / kg, the WS1.4 value of the modified diesel fuel decreases to 189 μm (see wear scar photograph in Fig. 7), and the lubricity of the modified diesel fuel is obviously improved. This effect is unexpected and demonstrates that there is a significant synergistic effect between monoisooctyl maleate and linoleic acid in the composition obtained in Example 1. On the other hand, the composition obtained in Comparative Example 1 by mixing diisooctyl maleate and linoleic acid in the same weight ratio shows an unsatisfactory effect of improving the lubricity and does not show any synergistic effect.

[0231]

[0232] As can be seen from the results in Table 5-2:

[0233] 1) When 100 mg / kg of monoisooctyl maleate is individually added to diesel fuel B, the WS1.4 value of the modified diesel fuel is 412 μm; when 100 mg / kg of unsaturated fatty acid glyceride JC-2017Z is individually added to diesel fuel B, the WS1.4 value of the modified diesel fuel is 459 μm; whereas, when 100 mg / kg of the composition of Example 2 is individually added to diesel fuel B, the wear scar diameter WS1.4 of diesel fuel B unexpectedly decreases to 305 μm, demonstrating that monoisooctyl maleate and unsaturated fatty acid glyceride JC-2017Z, which are present in the composition of Example 2, exhibit a significant synergistic effect;on the other hand, the compositions obtained in Comparative Example 2 using diisooctyl maleate and the composition obtained in Comparative Example 3 using monoisooctyl dodecenyl succinate exhibit the effect of improving lubricity to a significantly lesser extent than the composition of Example 2, and to an even lesser extent than individual component B, demonstrating that there is no synergistic effect between the components in the compositions of Comparative Examples 2-3;

[0234] 2) within the range of the mass ratio of components A and B according to the description of the present invention, the compositions in all examples exhibit an excellent effect of improving the lubricity;

[0235] 3) when component B is an ester of a polyhydric alcohol and a long-chain fatty acid, the composition obtained in Example 5 using monoisooctyl maleate exhibits a more significant effect of improving lubricity than the composition of Example 3 using monoisooctyl itaconate and the composition obtained in Example 4 using methyl ricinoleate substituted with a phthalic acid monoester, when using the same amount, the same component B and the same weight ratio of components A and B; and

[0236] 4) the composition of example 6, in which the mass ratio of components A and B is 4:6, produces a significantly greater effect of improving the lubricity than the composition of example 5 and the composition of example 8, which have a larger mass ratio of components A and B, and the composition of example 7, which has a smaller mass ratio of components A and B, when using the same component A, the same component B and the same amount.

[0237]

[0238]

[0239]

[0240] As can be seen from the results in Table 5-3:

[0241] 1) when component B is a long-chain fatty acid, the composition obtained in Example 9 using monoisooctyl succinate exhibits a more significant effect of improving lubricity than the composition obtained in Example 11 using monobenzyl maleate; the composition obtained in Example 17 using monoisooctyl maleate exhibits a more significant effect of improving lubricity than the composition obtained in Example 10 using mono-tert-butyl malonate;the composition obtained in Example 14 using monoisooctyl maleate exhibits a more significant effect of improving lubricity than the composition obtained in Example 13 using methyl ricinoleate substituted with the monoester of maleic acid, and an even more significant effect than the composition obtained in Example 12 using methyl ricinoleate substituted with the monoester of methyl tetrahydrophthalic acid, when using the same amount, the same component B and the same weight ratio of components A and B;

[0242] 2) within the range of the mass ratio of components A and B according to the description of the present invention, the compositions in all of the examples exhibit an excellent effect of improving lubricity, and the composition of Comparative Example 4 in which the mass ratio of components A and B is 9.5:0.5 and the composition of Comparative Example 5 in which the mass ratio of components A and B is 0.5:9.5 exhibit a significantly smaller effect of improving lubricity than the compositions in Examples 9 to 21, and an even smaller effect than the individual component A, demonstrating that there is no synergistic effect between the components in the compositions of Comparative Examples 4 to 6;

[0243] 3) when component B is a long-chain fatty acid, when using the same component A and the same component B, when adding a composition in which the mass ratio of components A and B is 1:9 (see, in particular, Example 15) in a total amount of 120 mg / kg (content of 12 mg / kg of component A), the wear scar diameter of diesel fuel can be reduced to 398 μm, while when 12 mg / kg of component A is added individually, almost no effect of improving lubricity is exhibited (643 μm);when adding a composition in which the mass ratio of components A and B is 2:8 (see, in particular, example 16) in a total amount of 120 mg / kg (content of 24 mg / kg of component A), the wear scar diameter of diesel fuel can be reduced to 367 μm, while when adding 24 mg / kg of component A individually, an unsatisfactory effect of improving lubricity is shown (601 μm), and when adding 120 mg / kg of component B individually, an unsatisfactory effect of improving lubricity is also shown (497 μm), demonstrating that component A and component B have a synergistic effect;when used in the same amount, the composition of example 20, in which the mass ratio of components A and B is 7:3, exhibits a higher effect of improving the lubricity than when using the composition of example 21, which has a higher mass ratio of components A and B, and the compositions of example 18 and example 14, which have a lower mass ratio of components A and B; and the composition of example 19, in which the mass ratio of components A and B is 6:4, exhibits a higher effect of improving the lubricity than the composition of example 17, in which the mass ratio of components A and B is 4:6.

[0244]

[0245]

[0246]

[0247] From the results shown in Table 5-4, it can be seen that all the lubricity improving compositions according to the present invention containing various components A and B produce an excellent lubricity improving effect, in which they are significantly superior to component A and component B used individually, and can also significantly improve the lubricity of diesel fuel in a very small amount.

[0248] Thus, the results of the study show that in the lubricity improving composition according to the present invention, component A and component B produce an obvious synergistic effect after being mixed in a certain ratio and improve the effect on the lubricity of diesel fuel to a much higher degree than component A and component B acting individually, and as a result, the added amount of the lubricity improving composition according to the present invention can be significantly reduced, and the cost of the required composition for improving the lubricity of diesel fuel can be reduced in order to ensure the required performance characteristics, and the risk of side effects caused by the addition of this composition can be reduced.

[0249] The present invention has been illustrated in detail above in this document with preferred embodiments, but the present invention is not intended to be limited to the embodiments shown. Various modifications can be made in accordance with the inventive idea of ​​the present invention, and such modifications are within the scope of the present invention.

[0250] It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and in order to avoid unnecessary repetition, various possible combinations are not described in the present invention, but such combinations should also be within the scope of the present invention.

[0251] Furthermore, various embodiments of the present invention can be arbitrarily combined as long as their combination does not deviate from the idea of ​​the present invention, and such combined embodiments should be regarded as the disclosure of the present invention.

Claims

1. A composition for improving the lubricity of diesel fuel, comprising: component A: a dicarboxylic acid monoester selected from dicarboxylic acid monoesters represented by the following formula (I-1): in which n is an integer from 2 to 6, R is a hydrocarbyl group C 3-20 , and selected from maleic acid monoester, fumaric acid monoester, citraconic acid monoester, methylfumaric acid monoester, 2,3-dimethylmaleic acid monoester, glutaconic acid monoester, or any combination thereof, or complex monoesters of dicarboxylic acids represented by the following formula (I-2): in which p is an integer from 1 to 8, R is a hydrocarbyl group C 3-20, and selected from a malonic acid monoester, a succinic acid monoester, a glutaric acid monoester, an adipic acid monoester, an azelaic acid monoester, a sebacic acid monoester, or any combination thereof, or complex monoesters of dicarboxylic acids represented by the following formula (I-4): in which R8 is a divalent hydrocarbyl group C 2-10 ; R9 represents a hydrogen atom or a hydrocarbyl group, R 10 is a divalent hydrocarbyl group, and the total number of carbon atoms in the R9 and R groups 10 ranges from 15 to 21, and the total number of double bonds between carbon atoms ranges from 0 to 3; R 11 represents a hydrogen atom or a hydrocarbyl group C 1-10 ; And component B: long-chain fatty acid C 8-24, the corresponding ester of a polyhydric alcohol or a mixture thereof, wherein the total amount of component A and component B is 100% by weight, the mass ratio of component A and component B is from 9:1 to 1:

9.

2. The composition according to claim 1, wherein component B is a long-chain fatty acid C 8-24 , and the weight ratio of component A to component B is from 8:2 to 2:8, preferably from 7:3 to 3:7, and more preferably from 7:3 to 5:

5.

3. The composition according to claim 1, wherein component B is an ester of a polyhydric alcohol and a long-chain fatty acid C 8-24 , and the weight ratio of component A and component B is from 8:2 to 1:9, preferably from 8:2 to 2:8, and more preferably from 5:5 to 2:

8.

4. The composition according to claim 1, wherein component B is a long-chain fatty acid C 8-24, and the composition contains from 20 to 80 wt.%, preferably from 30 to 70 wt.% and more preferably from 50 to 70 wt.% of component A, and from 20 to 80 wt.%, preferably from 30 to 70 wt.% and more preferably from 30 to 50 wt.% of component B, based on the weight of the composition.

5. The composition according to claim 1, wherein component B is an ester of a polyhydric alcohol and a long-chain fatty acid C 8-24 , and the composition contains from 10 to 80 wt.%, preferably from 20 to 80 wt.% and more preferably from 20 to 50 wt.% of component A, and from 20 to 90 wt.%, preferably from 20 to 80 wt.% and more preferably from 50 to 80 wt.% of component B, based on the weight of the composition.

6. The composition according to any one of claims 1 to 5, wherein the dicarboxylic acid monoester having formula (I-1) is a maleic acid monoester.

7. The composition according to any one of claims 1-5, wherein the dicarboxylic acid monoester having the formula (I-2) is a malonic acid monoester, a succinic acid monoester, an adipic acid monoester, or any combination thereof.

8. The composition according to any one of claims 1-5, in which in formula (I-4) R8 is a divalent hydrocarbyl group C 2-10 ; R9 represents a hydrogen atom or a hydrocarbyl group, R 10 is a divalent hydrocarbyl group, and the total number of carbon atoms in the R9 and R groups 10 ranges from 15 to 21, and the total number of double bonds between carbon atoms ranges from 0 to 3; R 11 represents a hydrogen atom or a hydrocarbyl group C 1-10 , preferably a hydrogen atom or a hydrocarbyl group C 1-4.

9. The composition according to claim 8, in which in formula (I-4) ethylene, vinylene, methyleneethylene, methylethylene, butylene, methylbutylene, butenylene, phenyl, cyclohexyl, methylhexahydrophenyl or methyltetrahydrophenyl is selected as R8, and R 11 the hydrogen atom methyl or ethyl is selected.

10. The composition according to claim 9, wherein the dicarboxylic acid monoester having the formula (I-4) is methyl ricinoleate substituted with maleic acid monoester, ricinoleic acid substituted with maleic acid monoester, methyl ricinoleate substituted with succinic acid monoester, ricinoleic acid substituted with succinic acid monoester, methyl ricinoleate substituted with phthalic acid monoester, methyl ricinoleate substituted with methyl hexahydrophthalic acid monoester, methyl ricinoleate substituted with methyl tetrahydrophthalic acid monoester, or any combination thereof.

11. The composition according to any one of claims 1 to 5, wherein the dicarboxylic acid monoester of component A is monobutyl maleate, monoisooctyl maleate, monoisononyl maleate, monoisooctyl citraconate, methyl ricinoleate substituted with the monoester of succinic acid, ricinoleic acid substituted with the monoester of succinic acid, methyl ricinoleate substituted with the monoester of maleic acid, ricinoleic acid substituted with the monoester of maleic acid, methyl ricinoleate substituted with the monoester of methyl tetrahydrophthalic acid, or any combination thereof.

12. The composition according to any one of claims 1-11, wherein the unsaturated fatty acid in component B is selected from unsaturated fatty acids C 12-20 or any combination thereof, and ethylene glycol, glycerin, 1,2-propylene glycol, 1,3-propylene glycol, sorbitan, pentaerythritol, trimethylolpropane or any combination thereof is selected as the polyhydric alcohol.

13. The composition of claim 12, wherein the unsaturated fatty acid in component B is selected from oleic acid, linoleic acid, linolenic acid, ricinoleic acid, or any combination thereof, or a mixture of fatty acids is selected that primarily contains oleic acid, linoleic acid, linolenic acid, and ricinoleic acid, and the polyhydric alcohol is glycerol.

14. The composition according to any one of paragraphs 1-13, in which in formula (I-1) R represents a hydrocarbyl group C 4-18 ; in formula (I-2) R represents a hydrocarbyl group C 4-18 ; in formula (I-4) R represents a hydrogen atom or a hydrocarbyl group C 1-4 .

15. A method for improving the lubricity of diesel fuel, comprising adding to low-sulfur diesel fuel a composition for improving the lubricity of diesel fuel according to any one of claims 1-14, wherein the composition for improving the lubricity of diesel fuel is added in an amount of from 10 to 400 parts per million relative to the weight of low-sulfur diesel fuel.

16. The method of claim 15, wherein the composition for improving the lubricity of diesel fuel is added in an amount of 50 to 200 parts per million based on the weight of the low-sulfur diesel fuel.

17. A diesel fuel composition comprising low-sulfur diesel fuel and a composition for improving the lubricity of diesel fuel according to any one of claims 1 to 14, wherein the composition for improving the lubricity of diesel fuel is present in the diesel fuel composition in an amount of from 10 to 400 parts per million based on the weight of the low-sulfur diesel fuel.

18. The diesel fuel composition of claim 17, wherein the composition for improving the lubricity of the diesel fuel is added in an amount of 50 to 200 parts per million based on the weight of the low-sulfur diesel fuel.

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